Tiller and Alignment Check

      "I can pretty much look at the lines of a braced bow and tell you how it shoots"  John Schulz interview in Traditional Bowhunter Magazine

       So...you've got yourself a Hill style longbow or ASL and you're having fits getting the bow to shoot for you.  If you're shooting it correctly, a longbow of this type is extremely forgiving of shooting errors.  If the bow is tillered and aligned correctly that is...and if you're shooting it with proper form.  Let's address these in different approaches.

    First...Tiller and alignment.  Most people think of limb tiller as the way the limbs bend evenly when the bow is drawn. They go to a standard measurement of the spacing from the bow limb belly to the string at the points immediately above and below the handle fadeouts.  Most longbows of this style will be 1/8" - 3/16" positive tiller.  That means the gap from bow to string on the top limb will be greater than the gap at the same position on the lower limb.  But that's not the whole story.

     We have to have a baseline, a starting point because when the string is released, the limbs will attempt to get back to that position.  If that starting point is not equal from limb to limb, how can we ever expect the bow limbs to flex and recoil evenly?  So at brace, the first thing to do is trace the upper and lower limbs on some paper to see if they match.  They have to.  This is the starting point.  Now, the limb lengths are different in a proper longbow of this style and that will be explained later on.  So you actually trace the longer, upper limb from handle down the fadeout to the string groove while the bow is braced.  Then flip the bow over and lay the shorter lower limb on that tracing.  Align at the fadeout sweeps. If the limb arcs do not match, then the bow will probably never return to an equal brace height when the string is released from full draw.  The limb recoils rates will have to be adjusted by watching the bending of the limbs on a tiller board, but at the end of the recoil, they need to be arriving at the same point.  I hope that makes sense.  Just a measurement of tiller doesn't tell that story.  This is a check of the static limb tiller.

     Then you have to draw the bow and watch the limbs bending in unison and there should be no flat spots along the limbs where the limbs don't bend enough, or other places where the limbs look to bend too much.  They must bend equally as the bow is drawn and string released.  

     The above two factors affect the limb recoil timing.  If the limbs don't bend evenly...and if they do not return to the same even starting point, then the timing of the limbs will be off and consistent shooting will be nigh impossible, along with increased hand shock as a result.   Shooting a 12 grain per pound arrow or using a low stretch string with silencers will only mask what the issue is...improper tiller and timing.

     Limb alignment.  The string must travel from string nock to string nock in a straight line down the middle of each limb and though the center of the belly peak of the handle.  Period.  If not, the bow is not aligned.  In a self-wood bow, the limbs can be all wavy and if the string tracks through the center of the handle, the bow can be a good shooter, but there must be enough limb width material to counteract the off-alignment limbs.  In a narrow Hill style / ASL bow, there isn't that forgiveness.  The limbs have to align.  

    Most guys I've seen check alignment by sighting down the bow from end to end.  But they only get it half-way correct.  Schulz showed me that you have to hang the bow from the tips being supported on each end.  Properly done, you rest one limb tip on a support like a table top and hold the other tip lightly resting in your fingertips and let the bow handle hang down, string up.  Gravity pulls the bow vertical as you sight down the limbs and string.  There is no manipulation of the bow to make it align.  If there is any variation along the limb and the string doesn't track down the center of the limb, then the bow is out of alignment.  Can the bow be shot this way?  Sure. I've seen many, many longbows from major bowmakers with limbs terribly out of alignment...some as much as 3/4".  Depending on which direction the string tracks, it may be pushing the string into great alignment of the arrow, or maybe not.  But if the string does not push the arrow in a consistently straight path, in regards to their sight window and hand position on the bow, how can they expect to be accurate?   If you have good outdoor lighting and can get the sun to aid you,  you can position the bow to hang with the sun casting a string shadow on the belly of the limbs and that shadow line when lined up with the string above it, will show even better how the limbs are aligning.

      So now, hopefully you find that your bow is aligned and tillered correctly and you still can't shoot good groups.  One of the most important things to understand with the bow design is proper hand placement on the handle.  The lower limb is inherently shorter than the top limb due to the design because the middle of the bow isn't in the middle of the grip.  Our hand is putting pressure on the grip below center line, and our fingers are grabbing the string above the centerline.  So the bottom limb needs to be stiffer and the top limb weaker.  This is accomplished by making the limbs different lengths as a starting point.  If you grip the bow too loosely, this allows the stiffer lower limb to come back towards you as you don't bend it enough.  This throws the bow limbs out of dynamic tiller and timing.  Hill and Schulz taught to grab ahold of the bow, a little more firmly with the bottom two fingers as they are in line with the arm bones and are our gripping fingers of the hand.  This action helps keep the lower limb from bending back to the shooter and keeps the lower limb bending correctly during the shot.  It is important to that the length of the grip fits your hand.  If you have a short hand and a long handle grip area, you may have to position your hand in a different place on the handle to get the proper bending of the limbs which will then affect the dynamic tiller and your accuracy and overall bow shooting feel.

      This goes back to an early post about getting used to the Hill style / ASL and shooting it until it feels normal and comfortable before doing any arrow tuning.  Schulz said it's usually the archer that needs tuning, not the bow.  This means don't get too wrapped up in tuning and/or finding arrows that will shoot good out of the bow when you first start shooting it.  Check the static brace height limb tracing (with a brace height somewhere around 6") and string alignment first.  Make sure your bow is built well, or have a discussion with the bowyer.  Go out with some arrows that are close, and then just shoot them.  Don't shoot heavy logs, shoot a decent 8-9 gpp arrow, with no string silencers or bowquiver on the bow and just shoot 500 to 1000 shots getting the feel of the bow.  Don't be worried about erratic arrow flight at first.  Listen to the bow, get used to the feel, especially if you are accustomed to the feel of a recurve or D/R bow.  Let the bow tell you some things.  Once you're settled into it and it feels more natural, which takes a bunch more shooting that we usually account for, then you can start seeing which arrows fly good from it.  Chances are, you'll find there is quite the spine range of arrows that will fly straight...That's part of the forgiving nature of this longbow style.  If you don't dedicate yourself to shooting only that bow for awhile, and instead do the bow-du-jour approach, then you are only hurting your chances to really enjoy all this style of bow has to offer.

     More to come regarding shooting style and how it ties into the Hill style / ASL 's  longbow design.  Until then,

    Shoot straight.